1. Field of the Invention
This invention relates to a camera incorporating a zoom lens therein, and more particularly to a zoom lens suitable for a compact camera.
2. Description of the Prior Art
Compact cameras have many desirable features, for example they are small in size, are easily used and are inexpensive. With recent popularization of such compact cameras, compact cameras capable of higher functions and multi-functions are in demand. For example, cameras equipped with an AF (automatic focal adjustment) mechanism or a zoom mechanism have begun to appear in the market. Among them, are compact cameras having a zoom function capable of continuously varying the photographic magnification, in the hope in that a new market be found.
Most users of compact cameras are beginners and intermediate photographers. The cameras are often used for memorial photographs at family trips or group's trips. In these types of pictures, long distance photography is often used, and in case of utilizing a strobe, photography at close quarters or at a short distance is effected. Accordingly, it is desirable for the camera to be provided with the following two functions:
(1) Universality of photographic functions in a wide range from a short distance to a long distance, and PA1 (2) Readiness of operation.
It is thus contemplated that for (1) for the universality of photographic function, "a zoom lens system capable of continuously varying a focal length" within a predetermined range is used and (2) for the readiness of operation, "a pan focus system not requiring a focussing operation" is used. Specifically, a zoom lens is constituted so that a focal position of a zoom lens system comprising a plurality of lens groups is set in panfocus, so as to have a depth of field from a predetermined short distance to a long distance or an infinitedly long distance (.infin.).
However, when a zoom lens having both the panfocus function and zoom function is applied to a compact lens, both the functions are related to one another, and under this specific condition, their respective merits are possibly offset. Moreover, mounting of such a zoom lens on a compact lens should not affect the properties of small-size and light-weight which form features inherent in the compact lens.